This invention relates to the installation of electrical wiring and in particular, to a system for marking electrical wires and outlet box locations for accuracy and ease in connecting wires between the fuse or circuit breaker panel and the individual outlet boxes and to a method of wiring using the system. Typically the outlet boxes provide for electrical power connections switches or sockets or lighting, but the system is usable with any type of outlet box.
In a typical electrical construction, a wiring diagram provides the locations of a circuit breaker panel and a plurality of outlet boxes and an indication of the particular terminal on the panel to be connected to the component at each outlet box. At the present time, the electrician works from the wiring diagram and places a strip of numbered tape around each wire adjacent each end. The specific number of each wire is also marked on the wall or floor near the outlet box for the wire is typically using a crayon or chalk. After the numbered wires are installed in a conduit or otherwise as desired, one end of a wire is connected to the panel terminal corresponding to the number on the wire. The other end of the wire with the same number is positioned at the outlet box with the corresponding number, ready for installation of the light or switch or other component. Of course, a fuse panel with the same electrical connections can be utilized and where the term "breaker panel" or "circuit breaker panel" is used. "fuse" panels are also included.
Typically the wire ends are marked with peelable strips carrying the appropriate numbers, with the strips initially mounted on a paper or plastic carrier or substrate and with the strips being separably peelable from the carrier. A typical package of the wire marker number strips are shown in the U.S. Pat. No. to Welsh, 2,372,994. Various arrangements for mounting the marker strips on the carrier are shown in other U.S. Pat. Nos. including Brady, 2,681,732; Tobey et al, 2,818,168; Strachan, 2,831,277; Simmons, 2,906,397; Brady, Jr., 3,038,597; Wise, 3,361,252; Brady, 3,568 829; Brady, Jr. 3,896,246; Pointon, 4,391,853; Brown, 4,578,136; and Wrobel, 4,609,208.
In these prior number strip packages, the numbers are sequential and all strips are of the same color.
An electrical diagram of a typical circuit breaker panel is shown at 11 in FIG. 1. This arrangement is nearly universally used with both the low-voltage systems, such as 120/208 volts, and the high-voltage systems, such as 277/480 volts. In many construction projects, both low and high voltage sources are used, such as the lower voltage for appliance outlets and the higher voltage for lighting.
The panel 11 provides for 42 lines, with odd numbered terminals on the left and even numbered terminals on the right, with each line comprising a wire connected to one of the numbered terminals and a second wire connected to the neutral. The three phases of the power supply are identified as A, B and C and are known as the black, red and blue phases, respectively. Four colors of wire insulation are used, with black, red and blue for the hot wires and white for the neutral wire. As indicated by the dots in the crossings of the horizontal and vertical lines in the diagram 11, all wires connected to the A phase have black insulation, all wires connected to the B phase have red insulation and all wires connected to the C phase have blue insulation.
A similar arrangement is utilized with the higher voltage system with the A phase being brown, the B phase being orange and the C phase being yellow.
In use, a length of wire 12 with black insulation is provided with the marker number 1 at each end. One end of this wire is connected to terminal 1 at the panel and the other end of this wire is brought out at the outlet box adjacent the chalk mark 1. A red insulated wire 13 and a blue insulated wire 14 are similarly marked with numbers 3 and 5, respectively, and connected at panel terminals 3 and 5, respectively, and brought out at boxes marked 3 and 5, respectively. This procedure is continued for as many wires as are indicated by the wiring diagram.
In making such installations, the electrician must remember the wire colors and panel phases and terminals or make continuous reference to the wiring diagram in order to insure that proper wire connections are being made. There is always the chance for error, which sometimes can be expensive and/or dangerous.
The conventional method used by electricians for memorizing circuit number, phase and color, for a 3 phase 4 wire system, is to mentally visualize the color and circuit number in "divisions of 6"; thus: 6; 12; 18; 24; 30; 36; 42;=42 circuits.
The low voltage code is memorized as "BRB=BLK-RED-BLU=A-B-C; circuits 1 and 2=black; 3 and 4=red; 5 and 6=blue; etc." The high voltage is memorized in the same manner--"BOY=Brown-Orange-Yellow=A-B-C; circuits 1 and 2=brown; 3 and 4=orange; 5 and 6=yellow; etc." Then every 6th circuit is "C" phase (blue or yellow).
For example; when the question is asked "What color wire is circuit 28 on low voltage?", the required thought process is--closest "divisions of 6" to circuit 28=24 and 30; count forward: 25 and 26=BLK; 27 and 28=RED; count back: 30 and 29=BLU; 28 and 27=RED; and the answer is: 28=RED="B" phase.
The apprentice electrician is trained in this method, when pulling wire with a journeyman in the field. Using this method for memorizing color and circuit number can be confusing.
If a mistake is made by pulling the wrong color wire, imbalance of load will occur. Corrections must be made by repulling the right color wire to the right circuit. Such simple errors add up and can be costly in correction time.